Lens-testing instrument



Nov. 27; 1923. 15475515 W. c. scHLlTzER 1 LENS TESTING INSTRUMENT Filed Feb. 6. v1922 2 Sheets-Sheet 1 [INI/(1,120'. W

WIIIIIJIIIIIAE Nov. 27, 1923. 1,475,515

W. C. SCHLITZER LENS TESTING INSTRUMENT Filed Feb. 6, 1922 2 ySheets-Sheet 2 u m WaZZer .cer

ATTORNEY Patented Nov. 27, 1923.

titans WALTER C. SCHLITZER, lOI? RGCHESTER, NEW YORK. i

Lans-TESTING rnsrnnmnnr.

Application filed February 6, 1922.

To all rwhom t may concern.'

Be it known that I, WALTER C. SoHLrrznR, a citizen of the United States of America, residingv at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Lens-Testing Instruments, of which the following is a speciiication.

My inventlon relatesto a lens testing instrument, and has for its purpose to provide mechanism for determining accurately t-he focal length and cylindrical axis of a lens.

he primary object of the improvement is to aii'ord a practical and simple structure that can be economically manufactured and easily operated.

A further purpose of the invention is to provide a device with a' minimum number of parts necessary for accomplishing the intended purpose in an etlicient manner.

To these and other ends, the invention consists in the details and combinations or part-s that will appear clearly from the following description in conjunction with the accompanying drawings, the novel features being pointed out in the claims following the description.

In the drawings: Y

Figure 1 is a side elevation of an instrument incorporating a preferred embodiment of the invention;

Figure 2 is a plan view of the same;

Figure 3 is a diagram of the optical sys-- tem of the instrument;

Figure 4 is a rear elevation of the supporting means for the test lens; f

Figure 5 is a horizontal sectional view on line 5 5 of Figure 4;

Figure l6 is a vertical sectional view on line 6 6 of Figure 1, with the lamp housing in elevation;

Figure 7 is a horizontal sectional view on line 7-7 of Figure 6;

Figure 8 is a vertical sectional view on the line 8-8 of Figure 2;

Figure 9 is a sectional view on the 'line 9-9 of Figure 1;

Figure 10 is asectional view on the line 10-10 of Figure 2;

Figure 11 is a sectional View on the line 11--11 of Figure 1;

' Figure 12 is an enlarged sectional view on the line 7-7 -of Figure 6, and

Serial No. 5345610.

Figure 13 is an enlarged elevation of a portion of the llens supporting means, showing a lens inposition but partially broken away.

In the illustrated embodiment, 1 designates a base upon which Vis mounted a standard 2, while 3 is a beam pivotally attached to the standardand held in adjusted position by awving nut t, so that it can be positioned at any angle to the horizontal, to

Y bring the sight tube at a convenient position with reference to the eye of the operator.

rIhe sight tube is attached at one end of the f test lens being lo- 'Ihe lamp housing 5 has an opening 7 at one side thereof, and 8 designates a collar that is frictionally retained on the housing over the opening 7 and is adjustable with reference to said opening. The collar 8 contains a light emitting pin-opening 9, which permits rays of light to pass 'trom the lamp housing directly onto the testv lens, to be referred to presently, and by adjustment of the collar 8, it is'possible to shift the opening 9 in--order that the light rays may be properly centered on the test lens. The collar 8 is held in adjustable and frictional engagement on the lamp housing 5 by a pin 10 actuated by a spring 1.1 against the housing, both said carried in a hollow handle member 12 carried by the collar, as shown in Figure 12.

The lamp housing 5 is mounted `on a plate or carrier 13, which has flanges 111- underlying the guide plate 15 which forms a part of the beam 3, the carrier 13. being slidableV along the beam untilthe proper focus of the test object on the image screen is obtained. The plate 15 is provided on its upper surface with proper focal length indicia, and the carrier 13 is cut away at 16 to afford indicators 17, which cooperate with the indicia 18 to show the focal length of a lens under test, one of said indicators cooperating with one set of markings forypositive pin and spring. being this, the adjustable sleeve lenses, and the other indicator and markings being for negative lenses.

Attached to one end oia the beam 3 isa bracket 19 to which the sight tubel is secured. 'lhe sight tube comprises a lined sleeve 20 rigidly attached to the bracket 19, and a second sleeve 2l which is rotatively attached to the lined sleeve Q0. To accomplish 21 has liXed toits inner end a collar 22, which telescopes within the iiXed sleeve 20 and is rotatable with reference thereto. interlocking means Vare provided between the sleeves 2O and 2l, preferably consisting` ot a spring tongue Q3 struck out and bent inwardly `trom the Y sleeve 2() and engaging a groove or recess 2d in the Vcollar 22. 25 designates an image screen, preferably ot ground glass or the like, held within the adjustable sleeve 2l against the collar 22 by means or a wire 26 which is iXedly secured to the sleeve 2l, and contacts `with the image screen, the wire 26 serving also the additional function of determining the anis of' the lens.

ln operating the device, the screen 25 isY rotated, by turning the sleeve. 2l, until the image,lconsisting of a line "formed by the spot of light passing through the test lens, appears parallel to the line 26. The angle of the cylindrical axis is determinable 'by means of a scale 28, which is preferably arranged on a plate 29 carried by the stationary sleeve 20, while the adjustable sleeve 2l carries a suitable indicator 30 cooperating with the stationary scale 28, the proper anis determiningV indicia or degree markings being disposed on the scale Q8. y

The means or supporting the test lens includes a bracket 3l removably engaging a hollow, split post 32 carried by the beam 3. Slidably mounted -on bracket 3l are plates 33, having lens engaging pins 34, and cut away at the center so as to lit against the collar 35 when in their normal or innermost position. When in testing position, the lens1 is positioned against the end of collar 85, as shown in Figure l, being held by the pins Se engaging its edge. Each plate 33 carries operating pins 86, orojectingthrough openings 37 to theV opposite side or 'bracket 3l, where they are engaged by bell-crank levers 38, slotted at 39 and pivoted to the bracket at 40. rlhe opposite end oit each bell-crank Vlever is also slotted at All to receive the end 42 of a controlling plunger a3, which is held u; in uppermost position byV a spring all. To spread the pins 34 when inserting a lens, the plunger i3 is depressed, swinging-tie bellcrank levers 38 and moving the platesv 33 outwardly, away from each other, all of said parts being restored to normal positicn by spring de when the plunger is released.

4:5 designates a supplemental lens mount pivoted on a post e6, and adapted to be swung into the longitudinal axis ci the focal sysarranged at the inner end ci" the sight tube,

that is, at the inner end cic the lined sleeve 20, and serving to project the image tromA the test lens onto the image screen Q5. T he lens l? is the only lens which the apparatusY necessarily employs, in addition to the lens under test, when a positive lens is being eX- amined, and by reterence to Figure 3, it will be observed from the pin opening or test object 9, directly to the test lens, whence they pass, converging slightly, to the condensing lens'l'?, the condensing lens l? acting to project the image onto the image screenQ. 4:8. designates an operating'handle mounted on the carrier 13, and preferably provided with rictional retaining means consistingfoit a spring actuated pin contacting with' the beam 3, similar to the means previously described, and illustrated in Figure 12'.

rlhe invention is ci' an` extremely simple and practical nature, and affordsy anaccurate means `for determining the focal length or cylindrical axis-of a lens, and vwhile l have shown the improvement in a preferred embodiment, it is susceptible of different modilications, and this applicationv is intended to cover any-changes or departures coming within the spirit of the.A improvement or the scope of the following claims.

l claim:

l. il. lens testing instrumentcomprising means for supporting a testA lens', a. lamp housing located on one side ot said lens supporting means and havin an opening at one side thereof, a sleeve arjustable on the housing and positionable over-said opening, the sleeve having a light emitting opening that is adjustable to proper relationshipwith the test lens and acts to project rays of light onto the test lens, a sight tube Von the opposide of the lens supporting. means, an image screen within the tube, and a condenslens between the image screen and lens supporting means.

2. rlhe combination with a.=lens testing instrument, or means for supporting a lens consisting of ay bracket, plates slidable laterally on said bracket towarl and from each other, lens engaging members carried by said plates, bell-crank levers connected to said plates, and a vertically movable s ringcontrclled plunger connected to sai bellcrank levers.

3. The combination with a lens testing instrumenno'l means for supporting a lens consisting of a pair ofhorizontally slidable plates, lens engaging members carried by said plates, operating pins mounted on the plates, bell-crank levers having slotted ends engaging said pins, the other endsot said bell-crank levers being slotted, anda vertithat the light rays passiso cally operable plunger engagingy the last mentioned slotted ends.

4. The combination With a'lens testing instrument, of means for supporting a, lens consisting of a collar against Which one surface of the test lens is positioned, a pair of slidable plates normally positioned against the sides of said collar, pivoted bell-crank levers connected to said plates, and a controlling plunger connected to said bell-crank l0 y levers. l

In Witness whereof, I have hereunto signed my name.

WALTER C. SCHLITZER. 

